Is your browser not open to full width and height? I'm on an 11" MBA, and didn't have to horizontally scroll at all (at 1366px wide), and I could see the end of the fold easily.

Regarding the disappearing scrollbars, I've actually added prompts for scrolling to a website, knowing that Lion, iOS and Android users wouldn't get a hint from visible scrollbars. (My biggest issue is the way horizontal scroll is so easily misinterpreted as a swipe [chrome in lion]. At least a few times a week I inadvertently go back a page...)